pH-responsive and sustained release drug delivery system of BSA coated CDs-DOX

Abstract Background The drugs are easily cleared and lack of targeting in chemotherapy, thus reducing its efficacy. A novel pH- responsive drug delivery system based on carbon quantum dots (CDs) was proposed. CDs have low toxicity and good biocompatibility and can be electrically combined with doxorubicin (DOX). The bovine serum albumin (BSA), an endogenousx substance, could be used as a protein model for constructing a novel lipoprotein-like nanocarrier. In this study, we introduced BSA into the drug delivery system and prepared a stable drug delivery system BSA@CDs-DOX. The system was characterized by UV-Vis, fourier infrared spectroscopy, transmission electron microscopy and fluorescence spectroscopy, and its stability, drug loading efficiency, coating efficiency and drug release in vitro were investigated. The release of drug from the system was tracked by the fluorescence properties of CDs. Results The stability of the BSA@CDs-DOX system was obviously enhanced in various environments. The in vitro release profile was prolonged, and the cumulative release ratio at pH = 5.0 was 7.5 times higher than that at pH = 7.4. The drug side effects on the normal cells were significantly reduced and the killing effect on cancerous cells was improved in longer time. Excellent and sustained migration resistance was observed in 72 h. The drug uptake process and cellular state were evaluated visually in real time until 72 h. Conclusion The stable and sustained release BSA@CDs-DOX system showed good application prospect in chemotherapy of tumors.